An Indian-led ultimatum to unravel a World Trade Organization deal struck in Bali last December would end global trade reform efforts, U.S. Ambassador Michael Punke warned in a speech to the Geneva-based body on Friday.

"Today, we are extremely discouraged that a small handful of members in this organisation are ready to walk away from their commitments at Bali, to kill the Bali agreement, to kill the power of that good faith and goodwill we all shared, to flip the lights in this building back to dark," Punke said.